Brook Lamprey Lampetra planeri are the smallest of the Lamprey species, measuring only 10 – 15cm. They are an eel shaped fish, with sucker-like mouth instead of jaws. Whilst they are an EU protected annexed species, they are widespread in Duhallow’s rivers and streams. They have a short life cycle of 3 – 5 years, starting with their juvenile phase (ammocoetes) when they eat detritus and other organic matter on the riverbed. When they reach their metamorphic stage, the Brook Lamprey cease eating and spawn in the substrate (redds). A few weeks after spawning, the adults die.